Hyperthermophilic archaebacteria have been isolated from solfataric and submarine hydrothermal systems (Kelly, R. M. & Deming, J. W.; Biotech. Progress, 4, 47-62 (1988)). It has been presumed that members of Pyrococcus and Thermococcus contain heat stable proteases and amylases (Stetter, K. O.; J. Chem. Technol. Biotechnol., 43(4), 315-317 (1988)), but proteases obtainable from members of Staphylothermus have never been predicted, isolated or in other ways investigated.